In military affairs, a long cylindrical tube for throwing projectiles by the explosion of gunpowder, of such dimensions as to require to be supported upon a carriage, with liberty to recoil after firing; in which circumstance it differs from fire-arms of the smaller sort, as pistols, carabines, etc. which may be fired from the hand or shoulder, and from an intermediate class, as musketoons, duck guns, etc, which are fired from a rest. The date of the invention, and the name of the inventor, are unknown: it is certain that Edward employed cannon at the battle of Cressy, a.d. 1346; but records are extant showing that they were known in France as early as the year 1338; and Isaac Vossius asserts that they were used in China 1700 years ago. For some time after the invention of cannons in Europe, they were formed of bars of wrought iron, fitted together lengthways, or of sheets of iron, rolled up and fastened together; and in both cases hooped with iron rings. They were extremely heavy and cumbersome, and principally used for throwing large stones to short distances, like the machines of the ancients which they succeeded.

These were gradually supplanted by brass cannon of much smaller calibre, and which threw iron and leaden balls instead of stones.

These guns were first cast of a mixture of tin and copper, and from that circumstance called gun-metal; but subsequently, as the use of cannon became more general, cast iron guns were used on account of their being much cheaper; and at present, guns for the naval service, and for batteries, are generally cast of iron, whilst field pieces and horse artillery, are mostly formed of brass. When the process of casting guns was first resorted to, the guns were cast with hollow chambers, which were afterwards perfected by boring; but the present practice is to cast them solid, and form the cavity entirely by boring. In 1828 a patent was granted to Mr. Joshua Horton, for a method of forming cannon, and other large cylinders, of wrought iron or steel, or mixtures of both. The process is as follows: - A number of bars a a are to be bound together by binding hoops b b, as shown in Figs. 1 and 3, and placed in a furnace. When they have acquired a welding heat, they are to be withdrawn and placed on a maundrel, and hammered together by heavy hammers, and if necessary, heated again until they are perfectly united; the bars should be wedge shaped, or wider on the outside than on the side which is to form the interior of the cylinder; but any of the forms shown in Fig. 1 will do.

If the cylinder is intended for a cannon, the bars should be thickest at the breach end; and if deemed necessary, the interior may be formed of steel, by placing a layer of steel bars within the iron bars. The breach-piece may either be formed in one piece with the rest, or it may be forged separately and screwed into the gun, as shown in Fig. 4. The trunnions may also be formed with the gun; but the patentee recommends that they should be formed in a separate ring, and attached to the gun either by an external screw cut on the gun, and fitting into an internal screw in the ring, as shown in Fig. 4, or by keys, as in Fig. 2. These separate trunnions the patentee recommends as possessing great advantages, from the facility with which the gun may be rendered useless by removing the trunnions, when necessary to abandon it to the enemy. After the welding is completed, the piece is to be finished by turning and boring. At the first mention of this method of constructing guns, it seems similar to that followed at the first introduction; but the earlier cannon formed of iron bars were merely hooped together, and not welded, as may be seen in several which are preserved at the Tower of London: nevertheless, it is certain that cannon of smaller calibre, forged of iron, were very early known.

In proof of this we may cite the following curious fact:- In the year 1827, a fisherman whilst fishing in a boat eight miles to the eastward of Calais, brought up in his net from the bottom of the sea a small piece of ordnance of a very singular construction, resembling exactly the representations of cannon in three ancient historical paintings in the dining parlour at Cowdry, in Sussex, one of the seats of the late Lord Viscount Montagu. The first painting represents the march of King Henry VIII. from Calais towards Boulogne; the second, the encampment of the English forces at Marqueson; and the third, the taking of Boulogne, in 1544. The resemblance will be instantly perceived by referring to the sketch on the following page; Fig. 1 representing the cannon as seen in the paintings, and the other figures exhibiting with all its details the cannon taken by the fisherman. Fig. 1 represents a carriage supporting two pieces of ordnance, which are nearly covered by a kind of hood in form somewhat like half a cone, the broadest end being next to the shafts, and the smaller end being constructed with sharp points; the hood probably being intended as a shield to protect the artillery men from the fire and arrows of the enemy, and the points as some defence against a charge.

Fig. 2 is a horizontal view of the new found gun; Fig. 3 a longitudinal section of the same; and Fig. 4 a bird's-eye view of it; l representing the tail bit, also of iron, forming part of the cannon, and serving to adjust it with ease in taking aim. The gun when first brought up from the bottom of the sea was covered with a sort of petrified rust, about two inches thick, which being removed, the diameter of the gun at the middle was found to be 3 inches, its bore for the passage of the bullet 1$ inch, and the length, including the tail-piece, 5 feet 11 inches, and its weight 64 lbs. Upon examination it was found to be still charged, having in it powder and a leaden bullet; from which circumstance we may conclude that cast iron balls were not known at the time when the cannon had been charged. The bullet had a covering of tow, and weighed 9 ounces; its diameter 1.4 inch. A A and C in Figs. 2, 3, and 4, are three different views of a shifting breech, which was detached and taken out of the after part of the gun when required to be loaded with powder; this being charged, and the cartridge properly secured by driving down an oaken plug over it, the bullet was put into the gun at the breech, and the shifting breech replaced in its original position, and firmly secured by an iron wedge D D D, Figs. 2, 3, 4, driven in behind it horizontally across the gun.

The shifting breech is shewn separately in Fig. 5, and the wedge in Fig. 6. E, Fig. 7, is the figure of the after part of the barrel of the gun, and F is the other half within the dotted circumference, this being cut off so as to take out and replace the shifting breech with facility, g g, Figs. 2 and 3, show the leaden bullet in front of the shifting breech. It is a remarkable fact that the shifting breech appertaining to this cannon is similar in principle to the patent shifting breech on some fowling-pieces of modern times.

Fig. 2.

Cannon 298

Fig- 1.

Cannon 299

Fig. 3.

Cannon 300

Fig. 4.

Cannon 301

Fig.1.

Cannon 302

Fig. 2.

Cannon 303

Fig. 3.

Cannon 304

Fig. 4.

Cannon 305

Fig. 5.

Cannon 306

Fig. 6.

Cannon 307

Fig. 7.

Cannon 308Cannon 309

We shall conclude this subject with a description of the apparatus employed for boring cannon. Formerly the cannons were suspended in sliding frames vertically over the boring tool, and the tool was made to revolve, the cannon descending gradually as the tool bored the interior; but in the present method of boring, the gun is supported horizontally in a lathe, and revolves, the cutter advancing in a right line. An apparatus of this description is represented in the accompanying figure. The cannon a is accurately centered in the chuck b, and the collar c, which may be set at any part of the bed d of the lathe to suit the length of the gun; e is the boring tool, supported by bearings in the frame f, and connected to the rack g. The rack is made to advance in a chase mortice h, by means of a pinion k actuated by a weighted lever l. The cannon is caused to revolve by a band passing over the rigger m, and the operations of boring the interior, and turning the exterior, are carried on at the same time.

Cannon 310